CVE-2026-89917: Linux

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping While VNCR TLB invalidation always occurs under the MMU lock, vcpu_put() doesn't, while it unmaps the VNCR page. The problem is that the invalidation evaluates vncr_tlb::cpu to decide whether an unmapping needs to take place (cpu != -1) before performing it. On the other hand, this_cpu_reset_vncr_fixmap() unconditionally unmaps if L1_VNCR_MAPPED is set. These two obviously can race, with a TOCTOU pattern on the TLBI path, and a BUG_ON() on the vcpu_put() path. And the two can end-up calling vncr_fixmap(-1), with extra lethal effects. Move the reset of vncr_tlb::cpu to -1 to a common function, and make this update atomic so that only a single thread can reset the field and perform the corresponding unmap. The vcpu_put() still need to unconditionally unmap the current VNCR to close another ugly race. Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync with the actual mapping, similar to L1_VNCR_MAPPED being set.

Засегнати продукти

• Linux Linux: 7270cc9157f474dfc46750a34c9d7defc686b2eb преди 5cbd8761d001c11ada73b1753d772c4745a70e72; 7270cc9157f474dfc46750a34c9d7defc686b2eb преди 9065c1261f8a05c6a7a2d90048c7c0665ab2896d; 7270cc9157f474dfc46750a34c9d7defc686b2eb преди 38640bc32be3fcf9526d477155bc19d3f146231f
• Linux Linux: 6.16; преди 6.16; 6.18.52 до 6.18.*; 7.2.5 до 7.2.*; 7.3 до *

История

Други уязвимости в Linux Linux

• 8.1CVE-2026-99270
• 7.8CVE-2026-99269
• CVE-2026-99268
• CVE-2026-99266
• CVE-2026-99267

Първоизточници

• https://www.cve.org/CVERecord?id=CVE-2026-89917
• https://nvd.nist.gov/vuln/detail/CVE-2026-89917
• https://git.kernel.org/stable/c/5cbd8761d001c11ada73b1753d772c4745a70e72
• https://git.kernel.org/stable/c/9065c1261f8a05c6a7a2d90048c7c0665ab2896d
• https://git.kernel.org/stable/c/38640bc32be3fcf9526d477155bc19d3f146231f